Crash safety awareness in vehicle interior developments
- Feb. 27, 2015
- Marcel Romijn
Where typically crash safety in interiors is only considered as being something for the seatbelts and the airbags there is a lot more to it. For example with the upcoming Volvo XC90 one of the large safety inventions was actually in the seat. When a vehicle leaves the road in an accident a large shock upwards often occurs which is an injury causing event. Volvo build a special seat mounting that can act as a shock absorber. Many years before also the other Swedish car brand, SAAB, had come up with the idea to put a mechanical system in their seats to prevent injury in case the vehicle got rear ended. We asked BRACE Automotive Engineer Franck Laudamy to provide some insight in how parts of a vehicle interior must be designed with crash safety in mind.
What is your position at BRACE Automotive and how long have you been working in Automotive Engineering?
Franck: “I am a Project Leader, specialized in mechanical engineering of tools and mold for the plastic injection. I have been working in automotive engineering for about fourteen years, with a background in mechanical engineering and mold maker.”
Are there laws or standards that tell what to do about crash safety?
Franck: “For vehicles to be allowed on road in Europe specific norms of the United Nations Economic Council for Europe must be fulfilled. Better known however and partially more stringent is the Euro NCAP crash test organization. The NCAP organization also has divisions in other countries. In the USA a similar situation exists where the NHTSA is regulating and additional tests are performed by the IIHS organization.”
Are the procedures for development also standardized?
Franck: “When we design interior components of vehicles and skins, we must take into account directly the norms. All components must meet the safety requirements. One specific example is the ECE R21 which describes the shapes and materials that can be used in impact areas. In other words any part that could collide with a part of the human body inside of the vehicle.”
How do you determine the requirements to interior parts in terms of crash safety?
Franck: “It is common approach to create digital models with all the internal components of the vehicle. With different software such as CATIA V5 and NX it is possible to simulate all possible position of impacts in the cockpit. The most critical part of the body is of course the head. The most dangerous components in a vehicle are the elements that may be moving. For example, the sun visor is an element that can be in several bad positions in case of accident. These components must be able to deform upon impact. The portion of the sun visor should be designed accordingly in order to meet the requirement of the standard and to ensure less body damage.”
Beyond actually crash testing a vehicle; what ways are there to verify the requirements per interior parts are actually met?
Franck: “The numerical simulation allows us to save time and money. With existing IT tools, it is possible to accurately simulate the points of impact and strain levels. With the study of motion, kinematics and FEA calculations, it's not essential to realize many real tests. Only a few trials to validate the numerical calculations are necessary. In the simulations for example the head of the human body is represented with a 165mm diameter sphere that can be impacting virtually all components in the vehicle interior. All components that can collide with the head of a passenger shall have a minimum radius required by the standard. Finally, once the CAD studies are finished, real prototypes are used for submission to the impact machine that allows to validate actual crash although not yet at a complete vehicle.”
What are the capabilities of BRACE in this field?
Franck: “BRACE engineers worked on several interior equipment projects. We always consider the design of components using rules and standards for the registration of vehicles. We support our customers in their design approaches and are very active in the field of consulting. Our expertise allows solving problems and finding creative and economical solutions.”